Track shoe



Aug. 5, 1947. R. Q. ARMINGTON 2,425,219

TRACK SHOE Filed Nov. 8, 1943 2 Sheets-Sheet l [I [III A. M 06 I7 g-l-EINVENTOR.

Rama/v0 Q ARM/NGTON nrromvsvs 1947. R. Q. ARMINGTON 2,425,219

TRACK SHOE Filed Nov. 8, 1945 2 Sheets-Sheet 2 /g INVENTOR.

AA wvo/vo Q. ARM/Nara BY H 22%.

ATTORNEYS Patented Aug. 5, 1947 TRACK SHOE Raymond Q. Armington, ShakerHeights, Ohio, asslgnor to The Euclid Road Machinery Co., Euclid, Ohio,a corporation of Ohio Application November 8, 1943, Serial No. 509,391

6 Claims. 1

This invention relates to improvements in crawler tracks of the typewherein rollers are provided intermediate the crawler frame and the shoewhich supports the same upon th ground. More particularly it relates toimprovements in means for supporting the rollers and for lubricating theroller bearings.

An object of the present invention is to provide simple but sturdy meansforsupporting a roller in a track shoe for the purposes described.

Another object of the invention is to provide a roller so supported thatit is easily removed when repairs are necessary.

Another object of the invention is to provide novel lubricating meansfor the bearings of the rollers and, more particularly, a novelcombination between the roller support and bearing lubricating means,

Other objects and advantages of the invention will b apparent from theaccompanying specification and drawings, and the essential featuresthereof will be set forth in the claims.

In the drawings,

Fig. 1 is a side elevation of a portion of an endless crawler trackembodying my invention;

Fig. 2 is an enlarged sectional view of the same taken along the line2--2 of Fig. 1;

Fig. 3 is a top plan view of one of the shoes of Fig. l with the rollerand tread pins removed.

Fig. 4 is a side elevational view of another form of track shoeutilizing my invention in a slightly modified form; the central portionof this view illustrates diagrammatically a detail of construction inconnection with Figs. 2 and 5.

Fig. 5 is a transverse sectional view similar to Fig. 2 showing a rollerand shaft assembled in the shoe of Fig. 4; while Figs. 6 and 7 aredetail views of certain parts of Fig. 5.

I have chosen to show my invention embodied in a crawler of the typeshown in a copending application of Stewart F. Armington, Serial No.493,555, filed July 5, 1943, now Patent No, 2,411,- 408, dated Nov. 19,1946, although it will be understood by those skilled in this art thatmy invention may be applied to other types of tracks.

In this type of crawler device a main frame Ill is adapted to be mountedby trunnions at the point It on the vehicle to be moved. This frame issupplied with parallel endless guide rails l2 adapted to be engaged byrollers l3 which in turn ar supported by shoes l4 which engage theground. There is a series of these shoes connected together by treadpins l5 and each shoe carries a set of rollers l3.

The shoes are of sturdy and novel construction and comprise a base plateI6 adapted to engage the ground and' carrying parallel side walls I!adapted to support the rollers. The base plate is preferably of heavysteel corrugated as shown at Ilia to add strength and stillness. Theside walls are preferably welded to the base plate and each side wall ispreferably bent in as shown at Ila, Fig. 3, to provide support for ahousing l8 for the tread pin. This housing is preferably a piece of pipewelded into position as shown in Fig. 3. At the opposite side of theshoe spaced bosses l9 consisting of short lengths of pipe are welded tothe base plate and to the side wall ll. It will be readily understoodthat when the track is assembled the box l8 of one shoe lies between thebosses IQ of the adjacent shoe and a tread pin l5 passes through alinedopenings in the bosses so as to tie adjacent shoes together after themanner of a hinge pin. Qne manner of securing the pins in place is shownin Fig, 3 where an expansible plug 20 engages in notched portions on theinner face of the boss l9 so as'to prevent withdrawal of the pin IS. Theshoe is further stiffened by means of a cross brace 2| which is weldedto the base plate and to the side walls IT. The shoe is furtherstifiened by turning up the lip 22 which is adjacent the brace 2|. Thebent portion Ila of the side walls is further strengthened and the shoeis stifiened by means of the diagonal braces 23 which are welded to thebase plate and to the side walls.

The rollers l3 which occupy an intermediate position between the shoes[4 and the frame 10 are best seen in Fig. 2. This roller structure issymmetrical about the line A--A and therefore one-half only has beenshown. It will be understood therefore that there are two rollers l3each engaging a guide rail l2 and the rollers are rigidly connectedtogether by a, cylindrical member 24 which preferably is a length ofpipe welded to a roller at each end. A shaft 25 extends from one sidewall I! to the other. This shaft is stepped down at 2511 to provide aseat for the roller bearing 26. The carriage of this bearing is held inposition by the nut 21 which is threaded in the outer end of the roller.The outermost end of the roller is further reduced in diameter at 25band there carries a flinger 28 adapted to prevent the entrance of dirtin any quantity at the open outer face of the nut 21,

Novel means is provided for supporting the very heavy loads transmittedthrough rollers l3 to the shoes M. At the same time this construction issuch that the shafts 25 are easily removed from the track shoes. To thisend each side wall II has rigidly secured thereto, as by welding, asemi-cir cular plate member 29 which extends around the lower half onlyof shaft 25 when shoe l4 engages the ground as shown at the bottom ofFig. l. The inner radius of the member 29 closely fits the shoulder 25bof shaft 25 and provides a large bearing surface for transmitting thecrawler frame load through roller l3 and shaft 25 to the shoe 14. Theshaft 25 is of such a length that it maybe inserted between the parallelside walls I 1. The shaft is then held in position by. a cap screw 30 ateach end. Each cap screw has a shank which passes through a hole ill) inthe side wall I! which is of larger diameter than the shank of the cap,screw. The cap screw then has threaded engagement at 3| with the shaft25. Thus, when the two cap screws 30 are pulled up tight against thewashers 32 the shaft 25 is held in position in the shoe. It will benoted that the cap screws merely hold shaft 25. in the proper pos tionwhile the load is transmitted through shaft 25 and member 29 to the sidewalls I! of the shoe.

Novel means is provided for lubricating the roller bearing 26. It willbe noted that there is a hollow space 33 opposite the end of the capscrew shank. Passageways 34 are drilled in the shaft so that lubricantmay travel from space 33 to the space 35 and thus reaci; e bearing 26.The cap screw is provided with a central passageway 30a whichcommunicates at its inner end with-the space 33 and at its outer end isprovided with a standard fitting 36 for feeding lubricant to thepassageway 30a. Thus lubricant to the fitting 38 under pressure maytravel to and be forced through the bearing 26.

Lubricant is held in the space around bearing 26, and dirt is preventedfrom entering this space, by the novel structure indicated generally at31. This structure is more fully described and claimed in my copendingapplication Serial No 493,528, filed July 5, 1943, to which referencemay be had for a complete description. Suflice it to say here that aring 38 tightly mounted on shaft 25 carries a composite sealing ring 39which resiliently engages a flat wearing face on the nut 21.

In Fig. 4 is shown a modified form of track shoe 40 capable of use in anassembly like that shown in Fig. 1. Normally a shaft similar to 25 and aroller performing the function of i3 in the first named modificationwould be assembled in this shoe but the same are omitted from Fi 4 toclarify,the description.

This shoe has a ground-engaging portion 40a across the center of whichis welded a ground gripping bar 40b which also serves to reinforce theshoe at the center. A pair of substantially parallel side walls 400 arewelded to the base portion 40a. At one end of the shoe a cross web 40dstiff ns the side walls. Hinge pin construction not shown is provided atthe pivot points We so that the shoes may be attached in an endlesstrack.

Referring to Fig. 5, a roller 4| comprising two end roller portions 4la(only one of which is shown) engages a track like that shown at l2 inFigs. 1 and 2. Tapered roller bearings 42 located symmetrically withrespect to the center line A serve to journal the roller on thesupporting shaft 43. At each end this shaft is provided with a sleeve 44for a purpose later to be described. Through the medium of the sleeve 44shown in Fig. 5, the end of the axle is firmly supported in asemi-circular cradle 45 which is rigidly mounted on the shoe side wall400 as by welding or the like. The form of this cradle is more clearlyseen in dot-dash lines in Fig. 4. It will be obvious that the shaft androller assembly including the sleeve 44 is adapted to be removed andinserted between the parallel side wall portions 400 when the cap screw46 is absent. As in the first described form of my invention, however,the assembly is completed after the shaft 43 reaches the position ofFig. 5 by inserting the cap screw 46 which is threaded at 46a to enter alike thread in shaft 43.

A look washer 41 keeps this cap screw from backing off.

As in the first described form of my invention, a lubricant passageway48 is provided in the cap screw communicating with passageway 49 in theshaft so that lubricant may be fed to the space 50 on the inside of thebearing 42. This lubricant works through the bearing past the roller anis prevented from escaping by the seal indicated generally at 5|. Thisseal also prevents the entranceof dirt to the bearings and is of a knowntype not requiring further description here.

One difference between the modification of Figs, 4 and 5 and my firstdescribed modification is that means is provided for holding the shaft43 and its connected parts under initial tension pressed into the cradle45 when the parts are assembled. I find that this insures a firm supporthold tolerances so close as to obtain a firm support of shaft 43 in thecradle 45. The means here utilized for obtaining the above mentionedtension is the positioning of the center B of th hole 52 in the sidewall portion 400 slightly below (say /e4 of an inch) the center 0 of theare which defines the radially innermost shoulder 45a of the cradle 45.The cap screw 46 is then so constructed that the threads 46a may be wellentered into the associated thread in shaft 43 befor the smooth shoulder46b ofthe cap screw engages in the opening 52. For instance, referringto Fig. 7, the shoulder D is of the same order as the dimension in Fig.4. As mentioned before, I find that /e4 of an inch fulfills my purpose.It results from this construction that as the screw 46 is drawn finallyinto the position of Fig. 5, shaft 43 and the associated sleeve 44 areforced downwardly as the shoulder 46b engages in opening 52. This wedgesthe parts against the cradle 45. It is obvious that the provision of theslight distance E between the centers B and C described in connectionwith Figs. 4 and 5 could be applied to the device of Fig. 2, where theshaft 25 engages directly against the cradle 26. In other words, theaddition of the sleeve 44 in Fig. 5 is not essential to the principle ofthe wedging action disclosed.

The central portion of Fig. 4 illustrates diagrammatically thisconstruction as applied to Fig. 2 as clearly as would another view. Thisconstruction of Fig. 2, using the above-mentioned teaching, would haveshaft portion 25b fitting into the cradle 29 in the position exactlyanalogous to the surface 45a whose center is C. The hole Hb in the shoeside wall I! is in the same position as the hole 52 of Fig. 4 and hasthe center B slightly below the center C. It results from thisconstruction that when the screw 30 enters the hole I"), the shaft 25 isforced tightly against the cradle 29.

The purpose of the sleeve 44 is to provide takeup in the bearing 42 whennecessary. In carrying out this object I provide on the opposite end ofshaft 43 (not shown) a sleeve exactly like 44 except that it is notthreaded on shaft 43 but instead snugly embraces the shaft. This ring atthe opposite end, however, abuts against the cone 42a of the bearing 42at the other end of the shaft, thus positively locating the cone on theright-hand end of the shaft. Then the sleeve 44, shown in Fig. 5, isturned somewhat further onto the threads 44a'so as to push the cone 42atoward the right as viewed in Fig. 5. The cap screw 46 shown in Fig. 5is then drawn up tightly so as to draw th wall portion 400 firmlyagainst the left-hand end of sleeve 44 so as to prevent the sleevebacking oif. The outer bearing races 42b at both ends of the shaft fitfirmly against corresponding shoulders in the roller 4|. Therefore bytaking up on the sleeve 44 shown in Fig. 5, th bearings at both therightand left-hand ends of shaft 43 are tightened. This is a very simpleand easy arrangementfor tightening the roller bearings 42. Milled slots44b are spaced about the periphery of the sleeve 44 so that a spannerwrench may be utilized to pull up the sleeve 44.

The purpose of the ring 52 of rubber or similar sealing material is toprevent the entrance of dirt at the end of the shaft. This ring isslightly compressed in the annular groove 440 of the sleeve toaccomplish this purpose! What I claim is:

1. In the combination of a track shoe and a roller carried thereby,shaft means for supporting said roller, a cradle rigid with said shoeand lying beneath the end of said shaft means, there being an axiallyextending threaded recess in the end of said shaft means, there being abolt hole in said shoe substantially alined with said recess, and a boltsnugly fitting said hole and threaded in said recess, the center of saidhole being slightly below the center of said recess when said shaftmeans normally rests on said cradle, whereby when said bolt fully enterssaid threads said shaft means is wedged against said cradle.

2. A track shoe having a ground-engaging portion and spaced side Walls,a shaft non-rotatably carried by said shoe, a roller rotatably carriedby said shaft and adapted for carrying a load, said shaft being of alength to pass into and out of normal position between said side wallsand lying wholly between said side walls, means rigid with said shoesupporting said shaft on that side only of said shaft opposite therollerload, and removable means holding said shaft in position betweensaid side walls, whereby when said last named means is removed saidshaft and shoe may be separated at the side of said shaft opposite saidshaft supporting means by pulling said shaft out sidewise from betweensaid walls.

3. In the combination of a track shoe and a roller carried thereby,shaft means for supporting said roller, a cradle rigid with the shoe,wedging means for holding said shaft means wedged against said cradle,and said means holding said shaft means assembled in said shoe.

4. In the combination of a track shoe and a roller carried thereby,shaft means for supporting said roller, a. cradle rigid with the shoe,wedging means for holding said shaft means wedged against said cradle,said means holding said shaft means assembled in said shoe, and meanspassing through said wedging means for feeding lubricant between saidshaft means and said roller.

5. In the combination of a track shoe having parallel side walls and aroller-carrying shaft of length insufiicient to fill the space betweensaid walls, a sleeve threaded on the end of said shaft and extending thesame sufliciently to fill the space between said walls, a bearingbetween said shaft having tapered parts adjustable by relative movementaxially of said shaft, means holding one of said tapered parts, an innerportion of said sleeve engaging the other of said tapered parts so thatscrewing said sleeve on said shaft adjusts said bearing, and securingmeans outside one of said walls and engaging said shaft to hold saidshaft in said wall and holding said wall against the outer end of saidsleeve, whereby to hold said sleeve in its bearing-adjusting position.

6. The combination of claim 4 including a cradle rigid on said shoe andhaving an arcuate surface engaging the under side of said sleeve,whereby the larger area of said sleeve transmits load pressure to saidcradle.

RAYMOND Q. ARMINGTON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,561,996 Perry Nov. 17, 19252,206,966 Law July 9, 1940 1,793,190 Philips Feb. 17, 1931 1,362,910Zoeller et 8.1 Dec. 21, 1920 1,628,220 Berg May 10, 1927

